Submarine of the T class

P 311 was the only unnamed T-class boat, she was due to have been named Tutenkhamen but lost before she could be renamed. She was fitted to carry three Chariot human torpedoes.

HMS P 311 (Cdr. Richard Douglas Cayley, DSO and 2 Bars, RN) was lost while engaged in Operation Principle, the Chariot attack on Italian cruisers at La Maddalena. HMS P 311 left Scotland in November 1942 with sister-boats HMS Thunderbold and HMS Trooper after addition of human torpedo deck-mounted watertight containers, direct for Malta. P 311 departed from Malta on 28 December 1942. She sent her last signal on 31 December 1942 from position 38º10'N, 11º30'E. After this signal she was not heard from again and she is presumed sunk by Italian mines in the approaches to Maddalena on or around 2 January 1943. She was reported overdue on 8 January 1943 when she failed to return to base.

The wreck was found off Tavolara Island in 2015 by Italian diver Massimo Bondone. Apparently she fell victim to a minefield laid by the Italian minelayer Durazzo on 27.09.1941. See also this page (offsite link).

13 Sep 1942HMS P 311 (Cdr. R.D. Cayley, DSO and 2 Bars, RN) departed from Holy Loch for Plymouth. She has to be modified at the Devonport Dockyard to carry the containers that hold the Chariot human torpedoes. During the passage south through the Irish Sea she was escorted by HrMs Jan van Gelder (Lt. P.L.M. van Geen, RNN). (2)

12 Nov 1942HMS P 311 (Cdr. R.D. Cayley, DSO and 2 Bars, RN) departed from Port HHZ (on the North-West coast of Scotland) bound for Malta. She is not stop at Gibraltar so not to alert the German and Italian spies stationed in 'neutral' Spain on the Chariot containers on her deck.

Passage south through the Irish sea was made together with HMS Trooper (Lt. J.S. Wraith, DSO, DSC, RN). They were escorted by HMS La Capricieuse (Lt.Cdr. G.W. Dobson, RNR). (4)